The House of Representatives usually consists of 120 members of parliament (MPs), sometimes more due to overhang seats. 70 MPs are elected directly in electorate seats and the remainder are filled by list MPs based on each party's share of the party vote. New Zealand has universal suffrage – but does not allow sentenced prisoners to vote.[1] The form of New Zealand government essentially follows the Westminster system, and the government is led by the Prime Minister and cabinet who are chosen from amongst the members of the House of Representatives.

The parliament was established by the British New Zealand Constitution Act 1852 which established a bicameral legislature officially called the General Assembly, but usually referred to as Parliament. This produced a parliament very similar to Britain's, with a lower house, called the House of Representatives, and an upper house, called the Legislative Council. The members of the House of Representatives were elected under the First Past the Post system, while those of the Council were appointed by the Governor. Originally Councillors were appointed for life, but later their terms were fixed at seven years. This change, coupled with responsible government (whereby the Premier advised the Governor on Council appointments) and party politics, meant that by the 20th century, the government usually controlled the Council as well as the House, and the passage of bills through the Council became a formality. In 1951, the Council was abolished altogether, making the New Zealand legislature unicameral.

Under the Constitution Act, legislative power was also conferred on New Zealand's provinces (originally six in number), each of which had its own elected Legislative Council. These provincial legislatures were able to legislate for their provinces on most subjects. However, New Zealand was never a federal colony or dominion like Canada or Australia; Parliament could legislate concurrently with the provinces on any matter, and in the event of a conflict, the law passed by Parliament would prevail. Over a twenty-year period, political power was progressively centralised, and the provinces were abolished altogether in 1876.

Parliament received progressively more control over New Zealand affairs, through the passage of Imperial laws such as the Colonial Laws Validity Act, constitutional amendments, and an increasingly hands-off approach by the British government. Finally, in 1947, the Statute of Westminster Adoption Act gave Parliament full power over New Zealand law, and the New Zealand Constitution Amendment Act 1947 (UK) allowed Parliament to regulate its own composition. In 1986 a new Constitution Act was passed, restating the few remaining provisions of the 1852 Act, consolidating the legislation establishing Parliament and officially replacing the name "General Assembly" with "Parliament".

One historical speciality of the New Zealand Parliament was the country quota, which gave greater representation to rural politics. From 1889 on (and even earlier in more informal forms), districts were weighted according to their urban/rural split (with any locality of less than 2,000 people considered rural). Those districts which had large rural proportions received a greater number of nominal votes than they actually contained voters – as an example, in 1927, Waipawa, a district without any urban population at all, received an additional 4,153 nominal votes to its actual 14,838 – having the maximum factor of 28% extra representation. The country quota was in effect until it was abolished in 1945 by a mostly urban-elected Labour government, which went back to a one man, one vote system.[2]

The New Zealand Parliament is sovereign with no institution able to over-ride its decisions. The ability of Parliament to act is, legally, unimpeded. For example, the New Zealand Bill of Rights Act is a normal piece of legislation, it is not superior law as written constitutions are in some other countries. The only thing Parliament is limited in its power are on some "entrenched" issues relating to elections. These include the length of its term, deciding on who can vote, how they vote (via secret ballot), how the country should be divided into electorates, and the make up of the Representation Commission which decides on these electorates. These issues require either 75% of all MPs to support the bill or a referendum on the issue. (However, the entrenchment of these provisions is not itself entrenched. Therefore, Parliament can repeal the entrenchment of these issues with a simple majority, then change these issues with a simple majority.)[3]

The New Zealand House of Representatives has been the New Zealand Parliament's sole chamber since 1951. It is democratically elected every three years, with eighteen select committees to scrutinise legislation.[4]

The Legislative Council was the first legislature of New Zealand, established by the Charter for Erecting the Colony of New Zealand on 16 November 1840,[5] which saw New Zealand established as a Crown colony separate from New South Wales on 1 July 1841.[5] Originally, the Legislative Council consisted of the Governor, Colonial Secretary and Colonial Treasurer (who consisted the Executive Council) and three justices of the peace appointed by the Governor.[6] The Legislative Council had the power to issue Ordinances, statutory instruments.[7]

With the passing of the New Zealand Constitution Act 1852, the Legislative Council became the upper house of the General Assembly. The Legislative Council was intended to scrutinise and amend bills passed by the House of Representatives, although it could not initiate legislation or amend money bills. Despite occasional proposals for an elected Council, Members of the Legislative Council (MLCs) were appointed by the Governor, generally on the recommendation of the Prime Minister. At first, MLCs were appointed for life, but a term of seven years was introduced in 1891. It was eventually decided that the Council was having no significant impact on New Zealand's legislative process, and the terms of its members expired on 31 December 1950. At the time of its abolition it had fifty-four members, including its own Speaker.

In September 1950, the National government of Sidney Holland set up a constitutional reform committee to consider an alternative second chamber, chaired by Ronald Algie. A report produced by the committee in 1952 proposed a nominated Senate, with 32 members, appointed by leaders of the parties in the House of Representatives, in according to their strength in that House, Senators would serve for three-year-terms, and be eligible for reappointment.[8] The Senate would have the power to revise, initiate or delay legislation, to hear petitions, and to scrutinise regulations and Orders in Council but this was rejected by the Prime Minister, and the Labour opposition, which had refused to nominate members to the committee.[9]

The National government of Jim Bolger proposed the establishment of an elected Senate when it came to power in 1990, thereby reinstating a bicameral system, and a Senate Bill was drafted. Under the Bill, the Senate would have 30 members, elected by STV, from six senatorial districts, four in the North Island and two in the South Island. Like the old Legislative Council, it would not have powers to amend or delay money bills.[10] The House of Representatives would continue to be elected by FPP.

The intention was to include a question on a Senate in the second referendum on electoral reform. Voters would be asked, if they did not want a new voting system, whether or not they wanted a Senate.[11] However, following objections from the Labour opposition, which derided it as a red herring,[12] and other supporters of MMP,[13] the Senate question was removed by the Select Committee on Electoral Reform.

In 2010, the New Zealand Policy Unit of the Centre for Independent Studies proposed a Senate in the context of the 2011 referendum on MMP. They proposed a proportionally-elected upper house made up 31 seats elected using a proportional list vote by region, with the House of Representatives elected by FPP and consisting of 79 seats.[14]

Laws are initially proposed in Parliament as bills. They become Acts after being approved three times by Parliamentary votes and then receiving Royal Assent from the Governor-General. The majority of bills are promulgated by the government of the day (that is, the party or parties that have a majority in Parliament). It is rare for government bills to be defeated, indeed the first to be defeated in the twentieth century was in 1998. It is also possible for individual MPs to promote their own bills, called member's bills; these are usually put forward by opposition parties, or by MPs who wish to deal with a matter that parties do not take positions on.

If a Bill passes its third reading, it is passed by the Clerk of the House of Representatives to the Governor-General, who will (assuming constitutional conventions are followed) grant Royal Assent as a matter of course. Some constitutional lawyers, such as Professor Philip Joseph, believe the Governor-General does retain the power to refuse Royal Assent to Bills in exceptional circumstances – specifically if democracy were to be abolished.[15] Others, such as former law professor and Prime Minister Sir Geoffrey Palmer and Matthew Palmer argue any refusal of Royal Assent would lead to a constitutional crisis.[16]

Refusal of Royal Assent has never occurred under any circumstances in New Zealand. Once Royal Assent has been granted, the Bill then becomes law.